"I've been collecting Christmas carols ever since I can remember," says Rebecca Dwan, the nominal leader of the Old World Carolers, a loose affiliation of singers who share her enthusiasm for the seasonal songs. Most of the carols they perform cannot be found on tapes, CDs, or even old records, she continues, so "our mission is to put out these songs and get them back where families can learn them, almost like a folk song."

For the most part, their repertoire is drawn from the holiday traditions of Europe over a 500-year period from the 1300s to the 1800s. But it is not exclusively sacred or religious, Dwan adds.

"Definitely not all Christmas music has Christian meanings."

For the past 10 years, the informal chorus has met and rehearsed in Dwan's living room, learning carols from Russia, Spain, Portugal, and the Ukraine, as well as some more familiar melodies from central and western Europe. They have even worked up one number that is sung in Serbo-Croatian, which Dwan says is a small gesture in support of peace in that troubled region.

"It"s nice to remember that it's one language; two peoples but one language," she says.

The ethnic theme of their programs has been reinforced by the most visible venue in which the Old World Carolers perform, the Sonoma County Museum. "The first time I remember them being at the museum, we had scheduled an Italian holiday exhibit around Christmastime," recalls museum director Eric Nelson, "and they came in and sang Italian carols as part of the program.

"It set a wonderful tone and ambiance that we couldn't have possibly done without them."

That was seven years ago. The Carolers will mark their eighth Christmas with a program of traditional English carols this year, preparatory to the museum's Holiday High Tea the following day. "They add a breath of life and a more dramatic element to the programs that we've presented," Nelson adds.

In addition to the museum dates, the Carolers also sing at other private events and at convalescent hospitals, always donating their services. "We're about getting together to sing, not concertizing or performance," Dwan says. "Sometimes we"ll just get together and sing for fun, whatever we want."

Over the years, participation in the group has ebbed and flowed, some singers remaining constant while others come and go. Dwan, who has no formal training as a conductor, has tried to shape a leaderless group, but with only partial success.

"We try to stay in the folk process. We decide things by consensus," she explains. But when a downbeat is needed, she is usually the one to provide it, albeit somewhat reluctantly. "It's hard for people to break out of wanting a director," she sighs, "not just choirs, but any group.

"Some members just can't handle it and leave."

All singers are encouraged to bring their favorite carols to the group, which also functions as a sort of musical swap meet and is modeled on a Singers' Circle that Dwan happily took part in years ago when she lived in San Francisco. "I learned songs in that singers' circle that I've never forgotten. That tradition is one that I've tried to bring to this group."

No musical training is required of chorus members, and the group rehearses weekly through the fall months leading to the Christmas season.

The Old World Carolers now number about 16 voices, but only a couple of them are male, which imposes some limits on the repertoire they can perform. "I have wonderful music that requires men's voices," Dwan says wistfully. "When there are men here, then we can sing that music."

Still, she finds great satisfaction in what the Carolers are able to do. "The spirit that we started with in 1985 has pretty much stayed the same," Dwan says. "You get out of it what you put into it. In a way, the group is a real indulgence for me."

The Old World Carolers will perform Saturday, Dec. 9, at 1 p.m. at the Sonoma County Museum. Usual museum admissions will be in effect: $2 for adults, $1 for seniors and students, and children under age 12 free. The group will also sing Sunday, Dec. 10, at 4:30 p.m. outside the depot in Old Railroad Square as part of the Lights of Life program for Home Hospice of Sonoma County.